Also, can the same results be obtained using ArcMap as obtained by ArcGIS Pro? I notice that Pro has a dedicated workspace, with a way to utilize camera calibration and exterior orientation. Does ArcMap have these options? How about adding GCPs? Is there any guidance available anywhere? I'm willing to pay, if necessary.
1) for tutorials, yes. See here for drone imagery: Create Drone Imagery Products in ArcGIS Pro—Imagery Workflows | Documentation and here for scanned historical imagery: Create Scanned Aerial Imagery Products in ArcGIS Pro—Imagery Workflows | Documentation
2) regarding ArcMap vs. Pro, in general yes you can use ArcMap, since the geoprocessing (GP) tools used for Ortho Mapping in ArcGIS Pro are also available in ArcMap. However, I strongly recommend you use Pro for several reasons.
Without these graphical user interfaces in ArcMap, you can still enter coordinates for the fiducials and also for GCPs but that may require you to use other methods to identify the necessary coordinates.